1. Technical Field
The disclosure relates to a method for identifying and correcting drift of fuel and/or air quantity metering in an internal combustion engine.
2. Background Art
Measuring an exhaust-gas lambda value is one possibility for identifying a drift in the fuel metering or in the air quantity metering. This may be achieved by virtue of an estimated lambda value being calculated on the basis of a measured mass air flow and the original set value of the fuel quantity. The measured mass air flow may be determined by an mass air flow sensor, a so-called MAF sensor.
The drift of the MAF sensor with progressive service life may amount to up to +/−5%. The drift of the fuel injection quantity with progressive service life may amount to up to +/−15%. In background systems, it is not possible to determine whether the drift is to be attributed primarily to the parameter “air” or to the path of the MAF sensor or to the parameter “injected fuel” for example on account of a blocked injector or injector system or on account of wear of the injector or of the injector system.
The invention is therefore based on the object of providing a method of the type specified in the introduction, by means of which it is possible to determine which parameter the deviation is to be attributed to, in order to be able to reset said parameter in a targeted fashion.